RV Repair: Lower insullation beneath floor, particle board flooring, wet insulation

Question
I own a 2007 Coachmen "Spirit of America" 24ft. Had a situation where the water in the bath tub was left un-attended and water over flowed causing water to run forward across the vinyl flooring and towards front of RV. It was cleaned up in time but.....water seeped under particle board flooring and into lower insulation beneath floor. You could tell by looking under trailer that the water was caught and held by the black outer covering that holds the insulation in place. Needless to say, I had to cut outer covering to release trapped water and remove most of the wet insulation before mold or mildew set in. Now, I need to replace just a small section of flooring and reinstall the insulation underneath as well as the black covering which held it in place. Seems easy enough but would love to hear some suggestions on how to start. This is my first trailer and first project so I want to do it right.
Many thanks......Todd

Answer
Trailers are trailers once a guy at the factory told me they are one big mistake on wheels. lol
This is very straight forward the underbelly you can get at a rv shop and the floor decking cut it  out and brace your seams and relay the floor once you get into it you will under stand how they put it together. Just dont use any treated wood. use good grade lumber and youll be ok send pic if you need to

thanks and good luck